For the second time in 10 years the plastic molded water entry valve assembly screwed onto the back of our RV's Tetford toilet has developed super fine cracks in the valve's plastic assembly that leak fresh water onto the floor whenever the 12 volt fresh water pump is left on. Since there is no water shutoff valve just for the toilet, the RV's entire fresh water system has to be shut down in order to stop water from leaking from this failed plastic part.The first time I replaced it, the new plastic assembly from Tetford was a different material (black plastic) that I assumed was an improvement for reliability over the original assembly's teflon colored plastic material. I was wrong - it happened (micro crack leaks in the molded assembly) again on our recent trip.The micro cracks in this molded assembly are probably "caused" by the toilet's slight vibration motions when traveling - combined with the stress that the incoming stiff PEX water supply line places on the the assembly due to the stiff PEX line being bent in a curve just before it is screwed onto the valve assembly.Have any of you experienced this?Is there a permanent solution so this never happens again? i.e. How does one install a small length of very flexible water supply line between the female connector on the end of the fresh water PEX line and the mating male connector on the Tetford plastic assembly so that that a stiff incoming line doesn't stress the molded plastic valve assembly? So far I'm finding that interfacing PEX line connectors to other connector types is not all that easy to find adapters for.

Our RV is 12 years old without any problems. Do you winterize? If so, do you run antifreeze through the toilet valve assembly? I know from other peoples experience (our son :)) the toilet water valve is the weakest link when the temperature reaches freezing.

No freezing temperatures involved. We store our RV in our backyard here in Central CA and stick to Southwest travel in the winter. I'm pretty sure it's stiff PEX line stressing the valve assembly during travel. The toilet area is right in the rear of the coach where bouncing is worst.I guess I need help on how to interface a short piece of flexible water line between the stiff PEX line's connector and the plastic valve's water inlet connector.

Cut the piece of the PEX line and use a SharkBite push in connector to replace female connector that's in there now. This will also allow you to customize the length of flexible tubing to maximize the flexibility that you so desire.Home Depot and Lowe's have a wide selection of these fittings- - - toilet to PEX adapter etc. Lowe's carry a different brand and slightly cheaper.Good Luck

pnichols wrote:How does one install a small length of very flexible water supply line between the female connector on the end of the fresh water PEX line and the mating male connector on the Tetford plastic assembly so that that a stiff incoming line doesn't stress the molded plastic valve assembly?Simple. Buy a pump silencer kit like this which consists of two 3' lengths water hose terminated with factory fit 1/2" NPT connectors. Both Valterra and Shurflo offer their own versions ... use one of the hoses and that will provide the flex you need. If the existing PEX connector that connects to the toilet is in an awkward location cut the PEX tubing back a few inches and install a compression fitting from SharkBite or SeaTech. Can't take but a couple of minutes tops for this fix.

Terminate the pex supply pipe some distance from the toilet valve. Install a shutoff valve and a length of braided supply hose. If you have a female fitting on the toilet valve, you'll need an extra nipple to complete the run.

Micro-leaks in Tetford RV Toilet Water Entry Assembly

SoundGuy
Explorer
Sep 25, 2016
pnichols wrote:
How would a Tetford RV toilet removal/reinstallation be any different (other than the toilet being lighter in weight) than a residential one?

RV toilets, including Thetford use a rubber seal not wax as you would use with a residential toilet.

So far none of you have reported leaks from your RV toilet fresh water inlet valves due to them developing hairline cracks in the plastic material. Am I the only one to notice this manufacturing/design flaw?

Here in northern climates where winter temps drop well below freezing finding a cracked toilet water valve isn't uncommon at all ... my local dealer sells dozens of replacements each season when an owner discovers the winterizing job they'd done wasn't so complete after all. I've never heard of one stress cracking but hey, anything is possible ... just replace the valve, add a flexible braided line to the PEX so you don't have to deal with this again, and move on. :)
Chris_Bryant
Explorer II
Sep 25, 2016
Thetford uses a sponge rubber seal- slips over the "horn" of the toilet before reinstallation- no chance of misalignment. It is included with the water valve.

I have seen this failure, but I suspect it is due to stress on the valve from misaligned inlet tubing.
pnichols
Explorer II
Sep 25, 2016
I've removed and replaced toilets in my residence while we were building it. A new seal is required when reinstalling. I always bought a couple of seals for the reinstallation process because any distortion/squashing of the seal while replacing the residential toilet necessitated lifting the toilet back off and trying again - with another new seal.

How would a Tetford RV toilet removal/reinstallation be any different (other than the toilet being lighter in weight) than a residential one? I am trying to avoid going through that again with our RV toilet in order to replace the plastic valve assembly mounted on the back of it.

I'm curious ... for those of you who installed an RV toilet shutoff valve in your rig - why did you do it?

So far none of you have reported leaks from your RV toilet fresh water inlet valves due to them developing hairline cracks in the plastic material. Am I the only one to notice this manufacturing/design flaw?
SoundGuy
Explorer
Sep 25, 2016
pnichols wrote:
I also have to order a new valve, remove the old valve, and install the new valve. This is a VERY DIFFICULT job because of the close quarters in behind the toilet. I have to go pretty much by feel, use a mirror, and use a headlamp for light. I refuse to remove the toilet just to do this, even though it's difficult ... as that would be even more of a nightmare task.

You sure are insisting on turning this simple task into a monster it need not be. :S Turn the water off, undo the two flange bolts securing the toilet, and lift it out so you can work with it on your workbench. It's only a "nightmare" if you make it one. :R
happycamper002
Explorer
Sep 25, 2016
The problem with what you perceive a VERY DIFFICULT is you could end up with a half **s job. It would be more difficult to redo something that wasn't done right the first time.
Removing and reinstalling the toilet is not that hard and I'm not a plumber. I replaced mine and added a shutoff valve.
A piece of cake.
westend
Explorer
Sep 25, 2016
Most of the RV toilets I've had hands on or referenced have two fasteners in the closet flange, similar to a residential toilet. Removing the two fasteners shouldn't be a "nightmare".
pnichols
Explorer II
Sep 25, 2016
I also have to order a new valve, remove the old valve, and install the new valve. This is a VERY DIFFICULT job because of the close quarters in behind the toilet. I have to go pretty much by feel, use a mirror, and use a headlamp for light. I refuse to remove the toilet just to do this, even though it's difficult ... as that would be even more of a nightmare task.
SoundGuy
Explorer
Sep 25, 2016
pnichols wrote:
Is braided supply hose as long-lasting and indestructible as PEX tubing?

Good grief, you're WAY overthinking this. :R Cut the PEX, slide on a compression fitting, connect a length of braided hose like that I linked to earlier, connect it to your toilet, and you're done. Can't take but a few minutes, certainly far less time than you've wasted analyzing this to death already. :W
westend
Explorer
Sep 25, 2016
pnichols wrote:
Is braided supply hose as long-lasting and indestructible as PEX tubing?

This line into the toilet water supply valve will be pressurized whenever the water pump is turned ON which, overall, results in thousands of total hours of pressure in the line as the RV is used year after year. I assume that's the reason for PEX tubing in all of the RV's interior wall fresh water plumbing ... extremly long life under pressure. Is there any type of tubing more flexible than PEX that will hold up with this kind of use? Tubing price is almost no object for me in order to stop this irritating and trip-changing failure.

Adding a shutoff valve just for the toilet fresh water line is a must-have for us. However, valves themselves introduce a potential leakage point over time ... any suggestions on what small valve to use in the PEX or additional piece of flexible line that I install?
Millions of homes with multiple supply hoses and my trailer are left under pressure every day. If you're really paranoid about it get one of those "landlord" supply hoses that automatically shut if broken. I just buy the stainless braided hoses and have never had a problem. For a shutoff valve, I'd buy a brass ball valve.
Not knowing your plumbing skills, I'd suggest to visit the Sharkebite section at the big box store. It will probably have a valve in 1/2" to fit your pex pipe and it is a simple push onto the pipe. Make sure your cut pipe has no burrs.
pnichols
Explorer II
Sep 25, 2016
Is braided supply hose as long-lasting and indestructible as PEX tubing?

This line into the toilet water supply valve will be pressurized whenever the water pump is turned ON which, overall, results in thousands of total hours of pressure in the line as the RV is used year after year. I assume that's the reason for PEX tubing in all of the RV's interior wall fresh water plumbing ... extremly long life under pressure. Is there any type of tubing more flexible than PEX that will hold up with this kind of use? Tubing price is almost no object for me in order to stop this irritating and trip-changing failure.

Adding a shutoff valve just for the toilet fresh water line is a must-have for us. However, valves themselves introduce a potential leakage point over time ... any suggestions on what small valve to use in the PEX or additional piece of flexible line that I install?

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